Method of managing mobility management layer of a mobile device

ABSTRACT

After a mobility layer of a mobile device enters a waiting state, a timer T 3240  is activated. The mobile device is configured to await further instructions from a network system before the timer T 3240  expires and control the mobility layer to leave the waiting state if the timer T 3240  expires, thereby improving system efficiency.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application No.61/641,904 filed on May 3, 2012 and is a continuation-in-part of U.S.application Ser. No. 13/409,022 filed on 29 Feb. 2012, the entirety ofwhich is incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to a method of managing a mobilitymanagement layer in a mobile device, and more particularly, to a methodof managing a mobility management layer in a mobile device with improvedsystem efficiency.

2. Description of the Prior Art

According to 3GPP (3rd Generation Partnership Project) mobilecommunication structure, the wireless interface protocol structure of amobile device includes three layers: a physical layer, a data linklayer, and a network layer. The data link layer includes a packet dataconvergence protocol (PDCP) layer, a radio link control (RLC) layer, anda medium access control (MAC) layer. The network layer includes a radioresource control (RRC) layer, a mobility management (MM) layer and aconnection management (CM) layer.

The RLC layer is configured to provide services including protocol dataunit (PDU) transmission, automatic retransmission request (ARQ)correction, concatenation, service data unit (SDU)segmentation/reassembly/deletion, sequential PDU transmission,duplicative detection, protocol error detection, and protocolreestablishment.

The MAC layer is configured to provide services including hybridautomatic repeat request (HARQ) error correction and transmission timeinterval (TTI) bundling transmission.

The CM layer is configured to provide call controls, includingestablishing connection, selecting connection type (voice or fax) andreleasing connection, and manage supplementary service (SS) and shortmessage service (SMS).

The RRC layer is configured to maintain connection, establish/releasecommunication channel, and manage power control.

The MM layer is configured to handle user verification, signal encodingand all mobility-related functions so that the network may be informedof the current location of the mobile device.

According to current 3GPP specifications, after entering State 9, the MMlayer has a RR connection to its peer entity in the network, but no MMconnection is established. The mobile device is passive, awaitingfurther commands from the network. In the prior art, if the networksomehow fails to respond, the MM layer of the mobile device may stay inState 9 and thus is unable to provide other services.

SUMMARY OF THE INVENTION

The present invention provides a method of managing a mobilitymanagement layer in a mobile device. The method includes activating atimer of the mobile device after the mobility management layer enters awaiting state and the mobility management layer exiting the waitingstate according to a command received from a network before the timerexpires or the mobility management layer exiting the waiting state afterthe timer expires.

The present invention provides a method of managing a mobilitymanagement layer in a mobile device. The method includes activating atimer T3240 of the mobile device after the mobility management layerenters a state 9 “wait for network command” defined in a 3GPPspecification; and the mobility management layer exiting the state 9according to a command received from a network before the timer T3240expires or the mobility management layer exiting the state 9 after thetimer T3240 expires and entering a state 19 “MM idle”, defined in the3GPP specification by releasing a radio resource connection.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a state diagram illustrating the operation of the MM layer ina mobile device according to the present invention.

FIG. 2 is a flowchart illustrating a method of operating the MM layer ina mobile device according to the present invention.

DETAILED DESCRIPTION

FIG. 1 is a state diagram illustrating the operation of the MM layer ina mobile device according to the present invention. FIG. 1 depicts state3 “location updating initiated”, state 6 “MM connection activated”,state 7 “IMSI (international mobile subscriber identity) detachactivated, state 9 “wait for network command”, state 19 “MM idle”, andstate 25 “RR connection release not allow”. Since the present inventionis related to the operation of state 9, only relevant states aredepicted in FIG. 1. Other possible states of the MM layer are describedand explained in related 3GPP specifications (such as TS 24.008).

FIG. 2 is a flowchart illustrating a method of operating the MM layer ina mobile device according to the present invention. The method includesthe following steps:

Step 210: determine whether the MM layer is in a waiting state: if yes,execute step 220; if no execute step 210.

Step 220: activate a timer T3240 of the mobile device, execute step 230.

Step 230: determine whether the timer T3240 has expired: if yes, executestep 260; if no execute step 240.

Step 240: determine whether a specific command associated with exitingthe waiting state is received from a network: if yes, execute step 250;if no execute step 230.

Step 250: exit the waiting state and perform a first actioncorresponding to the specific command, execute step 270.

Step 260: exit the waiting state and perform a second action, executestep 270.

Step 270: reset the timer T3240, execute step 210.

In step 210, the waiting state may be state 9 defined in related 3GPPspecifications (such as TS 24.008). In state 9, the MM layer has a RRconnection to its peer entity in the network, but no MM connection isestablished. The mobile device is passive, awaiting further commandsfrom the network. In the embodiment illustrated in FIG. 1, the MM layermay enter state 9 after the mobile device performs actions A1-A4. ActionA1 is “RR connection established” in response to paging. Action A2 is“last connection release”. Action A3 is “store system info”. Action A4is “RR connection release not allowed”. If it is determined instep 210that the MM layer has entered the waiting state (such as state 9), step220 is executed for activating the timer T3240 of the mobile device, andstep 230 is then executed for determining whether the timer T3240 hasexpired.

In step 220 of the present invention, the timer T3240 is started afterthe mobile device enters the waiting state when:

-   the mobile device receives a LOCATION UPDATING ACCEPT message    completing a location updating procedure;-   the mobile device receives a LOCATION UPDATING REJECT message;-   the mobile device has sent a CM SEARVICE ABORT message;-   the mobile device has released or aborted all MM connections; or-   the mobile device enters the waiting state after receiving the    paging message from the network.

If it is determined in step 230 that the timer T3240 has not expired,step 240 is executed for determining whether the specific commandassociated with exiting the waiting state is received from the network.When receiving the specific command, step 250 is executed for exitingthe waiting state and performing the first action corresponding to thespecific command. In the embodiment illustrated in FIG. 1, the firstaction may be actions B1-B4. Action B1 is “RR connection release”according to a network command. Action B2 is “indicate MM connection”after receiving a first message. Action B3 is “MS (mobile station)deactivated and attach allowed”. Action B4 is “RR connection release notallow”.

If it is determined in step 230 that the timer T3240 has expired, step260 is executed for exiting the waiting state and performing the secondaction. In the embodiment illustrated in FIG. 1, the second action maybe action B5 “RR connection release” when the timer T3240 expires. Afterperforming the second action, the mobile device may enter state 19 “MMidle”.

In the embodiment illustrated in FIG. 1, the MM layer of the mobiledevice may enter a specific state corresponding to the specific actionafter exiting the waiting state. For example, after exiting state 9, themobile device may perform action B1 and enter state 19, perform actionB2 and enter state 6, perform action B3 and enter state 7, performaction B4 and enter state 25, or perform action B5 and enter state 19.After the MM layer exits the waiting state in step 250 or 260, step 270is then executed for resetting the timer T3240 before looping back tostep 210.

In an embodiment when the mobile device enters state 9 “wait for networkcommand” after receiving a paging message from the network, the timerT3240 is started. If the timer T3240 expires, the mobile device isconfigured to abort the RR connection and enter state 19 “MM idle”.

In the present invention, before the waiting period of the mobilitymanagement layer after entering a waiting state expires, the mobiledevice is configured to passively await further instructions from thenetwork. After the waiting period of the mobility management layer afterentering the waiting state expires, the mobile device is configured tocontrol the MM layer to exit the waiting state. If the network somehowfails to respond, the MM layer of the mobile device may exit the waitingstate for providing other services, thereby improving system efficiency.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A method of managing a mobility management layerin a mobile device, comprising: activating a timer of the mobile deviceafter the mobility management layer enters a waiting state; and themobility management layer exiting the waiting state according to acommand received from a network before the timer expires or the mobilitymanagement layer exiting the waiting state after the timer expires. 2.The method of claim 1, further comprising: determining whether thecommand associated with exiting the waiting state is received from thenetwork if the timer does not expire; and the mobility management layerexiting the waiting state and performing a specific action correspondingto the command when receiving the command.
 3. The method of claim 2,wherein the specific action includes an “RR (radio resource) connectionrelease” action, an “indicate MM (mobility management) connection”action, an “MS (mobile station) deactivated and attach allowed” action,or an “RR connection release not allow” action.
 4. The method of claim3, wherein the mobile device performs the specific action when receivingthe command if the waiting period does not exceed the predeterminedvalue, and the mobility management layer enters a state 3 “locationupdating initiated”, a state 6 “MM connection activated”, a state 7“IMSI (international mobile subscriber identity) detach activated, astate 9 “wait for network command”, a state 19 “MM idle”, and a state 25“RR connection release not allow” defined in a 3GPP (the 3rd GenerationPartnership Project) specification.
 5. The method of claim 1, whereinthe timer is a timer T3240 defined in a 3GPP specification.
 6. Themethod of claim 1, wherein the waiting state is a state 9 “wait fornetwork command” defined in a 3GPP specification.
 7. The method of claim6, further comprising: the mobility management layer exiting the waitingstate and releasing a radio resource connection if the timer expires. 8.The method of claim 7, further comprising: the mobility management layerentering a state 19 “MM idle”, and a state 25 “RR connection release notallow” defined in a 3GPP specification after releasing the radioresource connection.
 9. A method of managing a mobility management layerin a mobile device, comprising: activating a timer T3240 of the mobiledevice after the mobility management layer enters a state 9 “wait fornetwork command” defined in a 3GPP specification; and the mobilitymanagement layer exiting the state 9 according to a command receivedfrom a network before the timer T3240 expires or the mobility managementlayer exiting the state 9 after the timer T3240 expires and entering astate 19 “MM idle”, defined in the 3GPP specification by releasing aradio resource connection.